I’m not sure why I got this, but there was no way to log on using the domain admin account. I found this knowledgebase article http://support.microsoft.com/kb/162797 that states that I should

Log on locally as a local administrator. In the Network tool of Control Panel, select Change and enter a Workgroup name, leaving the domain. Restart the computer and log on locally as a local administrator.

There are two methods to rejoin the domain: You can join the domain from the client if at the same time you can provide an administrator username and password on the domain. -or-

You can delete the existing computer account in Server Manager, recreate the computer account, synchronize the domain, and then on the client rejoin the domain.

But what’s the local admin password for the ContosoSrv02 server? Turns out it can be found by heavy googling – and apparantly the local admin password for other Contoso Virtual Machines has been p@ssw0rd – and what do you know? It works for this machine as well!